The present invention relates to fish processing, and more particularly to a machine for automatically heading and gulleting fish, especially salmon, and transferring the fish from the machine for further processing.
When processing fish such as salmon it is necessary to behead the fish and then gullet the fish so that the membrane surrounding the salmon eggs or roe is broken, without excessively damaging the eggs. The eggs may then be removed prior to eviscerating and filleting the fish.
In the past, the heading and gulleting operations have been performed by hand. First, an operator would hold a fish by its tail end placing its head end beneath a V-shaped guillotine blade which would then be actuated by the operator to behead the fish. The operator would then pass the beheaded fish to a second operator who would again hold the fish by its tail end and force the open ended body cavity of the beheaded fish onto a rotating gulleting tool which would break the egg membrane. This second operator would then pass the fish to a third operator who would in turn feed it to an egg-saving and eviscerating machine. This manual procedure, however, is very labor intensive and thus expensive and time consuming. Additionally, there is no means for controlling the depth during the heading and gulleting operations other than the operator's experience . Thus, due to the difficulty of properly positioning different size fish with respect to the guillotine blade, meat loss remains a major problem as does excessive damage to the salmon eggs due to the difficulty in controlling the depth of manual insertion of the gulleting tool.
Various types of machines have been developed for heading fish. One such machine is manufactured and sold by Ryan Engineering Inc. of Seattle, Wash. In this machine, the fish are manually located on pins projecting upwardly from a moving conveyor belt by an operator. The fish are then moved downstream and sandwiched between this feed belt and a second belt to hold the fish in position for removing the head with a guillotine blade. This machine, however, has no gulleting station and thus gulleting of salmon still requires a manual operation as does feeding the gulleted fish to an egg saving and eviscerating machine. Additionally, this machine has no positive means for consistently controlling the depth of the guillotine cut.
Other heading machines are designed to produce a straight head cut on species with suitably located pelvic or pectorial fins such as perch, red fish, porgy, croaker, tilapia, mackeral, catfish and many others. In one of these machines, manufactured and sold by Pisces Industries Ltd. of Gladstone, Mich., an operator places the fish in a tray moving on a conveyor belt at an in-feed area. As the trays advance toward the cutting blade, the fish are automatically located by the pelvic or pectorial fin to insure correct position for the head cut. Immediately prior to the cutting blade, the trays grip the fish and hold it in position for the cutting operation. The head and body are then separately ejected from the machine for further processing.